Why are some snakes the same kind but some are venomous and some are not?

There are 55 different kinds of snakes in Mississippi and only six are venomous, according to the post. The six venomous snakes are Eastern Diamondback Rattlesnake, Copperhead, Canebrake Rattlesnake, Pigmy Rattlesnake, Cottonmouth and Coral Snake.

You can do a Google Picture search. Or, do a search of snakes in your state. But remember, DO NOT USE THE WORD POISONOUS! Snakes are either VENOMOUS, or NONVENOMOUS. And you should NEVERRR kill a snake. Even if it is venomous, and you have small children. Most bites occur while trying to kill a snake. And you will NEVER kill all of them, so why kill even one? Don't try to be a hero. There are too many DEAD heros already.

To identify venomous snakes quickly, without going too close, it helps to remember that they are fatter than harmless snakes, and usually taper at the neck and tail, while the non-poisonous varieties tend to be thinner and evenly shaped from head to toe, like a garden hose. Venomous snakes have a skinny neck and a diamond-shaped head, like a spade. They also tend to be more colorful, and aggressive. To play it safe, never provoke any snake; leave the area as fast as you can.

In the US a ring neck snake,not dangerous but don't handle it

In Australia a red bellied black snake, very venomous

a non venomous snake,we are fixya,not a snake reference

When I lived in Georgia I watched my dog jump at a snake every morning for two or three days. I looked it up and "thought" it was a rat snake. But this snake was really vicious! Turns out, it was a poisonous copperhead snake! What I am saying is that snake identification charts are not that easy to read. However, I learned that snake behavior is important!
According to WikiHow: "Copperheads. These beauties have a similar body shape to cottonmouths but are much brighter, ranging from coppery brown to bright orange, silver-pink and peach.[2] The young have yellow tails as well.

Check out their head shape. Non-venomous snakes have a spoon-shaped rounded head and venomous snakes will have a more triangular head.
The fact that you describe the snake you saw as long might be a good sign as most of the poisonous snakes I saw in Georgia had fat bodies.

According to SRELherp.UGA: Brown snakes are small -- 6-13 in. (17-33 cm) -- snakes that are usually brown, but can be yellowish, reddish, or grayish-brown. They usually have two rows of dark spots, sometimes linked, along the back and a dark streak down the side of the head. The belly is light brown to white.

Maybe this will help you: http://www.oplin.org/snake/quick%20id/quickid.html

Google water snake pictures. When the search page opens, select images. Lots of nice pictures, which you can save if you wish.

It can become a very poisonous venom that can injure someone on impact

The ring-necked snake or ringneck snake, Diadophis punctatus, is a species of colubrid snake found throughout much of the United States, central Mexico, and southeastern Canada. Ring-necked snakes are secretive, nocturnal snakes, so are rarely seen during the day time. They are slightly venomous, but their nonaggressive nature and small, rear-facing fangs pose little threat to humans who wish to handle them. They are best known for their unique defense posture of curling up their tails, exposing their bright red-orange posterior, ventralsurface when threatened. Ring-necked snakes are believed to be fairly abundant throughout most of their range, though no scientific evaluation supports this theory. Scientific research is lacking for the ring-necked snake, and more in-depth investigations are greatly needed.[3] It is the only species within the genusDiadophis, and currently 14 subspecies are identified, but many herpetologists question the morphologically based classifications. Diadophis punctatus

Snakes of Georgia Venomous snakes reptile removal of nuisance animals...